Scott Bolinger has released a boilerplate app that uses Angular and the Ionic Framework to create a generic WordPress site management mobile app.
It's available on Github for those that want to contribute or fork it for your own purposes. I was recently talking or writing (I can't remember which) about this exact need, and I'm really pleased to see Scott taking a first step toward a more independent WordPress app. As he notes in his own reasoning for taking this route versus contributing to the Automattic-lead WordPress app:
The existing WordPress apps are open-source, and I think that’s awesome. However, those apps are fundamentally different than the app I want to create, so simply contributing to them will not change how they are built. I am also not a native app developer, so I cannot contribute any code. Mostly I just thought making our own app would be fun!
His sample app is designed to run off the WordPress REST API. If you have experience with Angular and/or the REST API, Scott and the AppPresser team would love your contributions. You can do so via Github, and you can join their conversations in a new Slack at wp-app.slack.com, but ping Scott on Twitter @scottbolinger for an invite.